<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>js函数</title>
	<script type="text/javascript">
		
		// 函数的定义
		function aa(){
			alert('hello!');
		}

		// 函数的调用
		aa()
	</script>
</head>
<body>
	<input type="button" name="" value="弹框" onclick="aa()">
</body>
</html>